[Expression of a proliferation associated-nuclear antigen defined by Ki-67 monoclonal antibody in childhood acute leukemia]

Abstract

The growth fraction of childhood acute leukemia was evaluated by the immunostaining with the monoclonal antibody "Ki-67", which reacts with a nuclear antigen in proliferating cells. Ki-67 labeling rates (the percentage of Ki-67 positive cells in the total cells analyzed) greatly varied from patient to patient (0.0% approximately 49.2%). The mean value of the Ki-67 labeling rates was significantly higher in ALL than in ANLL (23.6% vs 5.6%, p < 0.001). In ALL, the Ki-67 labeling rates correlated with the proportion of S-phase cells determined by DNA flow cytometry (FCM) (r = 0.82) High Ki-67 labeling rates were preferably seen in ALL with favorable prognostic factors, although the correlation was not statistically significant. These results suggest that Ki-67 labeling rates reflect the differences in proliferative activity of bone marrow blast cells in childhood acute leukemia and is useful to determine the treatment schedule of cycle specific drugs.